October 15 Tax Extension Deadline: What Small-Business Owners Need to Do This Week
If you asked the IRS for more time to file your 2025 tax return back in April, the clock is almost out. Extended individual returns, and the extended returns of calendar-year C corporations, are due this Thursday, October 15, 2026. For many small-business owners, that one date covers both a personal Form 1040 with business income on it and, in some cases, the company's own return. Here is what the deadline means, who needs to act, and how to finish well even if your paperwork is not quite ready.
This post is general information, not individual tax advice. Every situation is different, so please talk with a tax professional about yours.
What the October 15 deadline actually covers
According to the IRS's guidance on filing extensions, an extension requested by the April due date gives you until October 15 to file without a late-filing penalty. That is the key word: file. The IRS is clear that the extension applies only to the return itself. Any tax you owed for 2025 was still due back in April, and interest has been building on unpaid amounts since then.
A recent Yahoo Finance report, republished from OregonLive, noted that as many as 20 million Americans request an extension each year. That is a lot of people facing the same week, and a lot of tax professionals with full calendars, so starting today matters.
Who should be paying attention
This deadline is especially important for:
Sole proprietors and single-member LLC owners who report business income on Schedule C.
Partners and S corporation shareholders who extended their personal returns while waiting on Schedule K-1s. Those business returns were due in September, so the K-1s should now be in hand.
Calendar-year C corporations that filed an extension for their 2025 corporate return.
Anyone who expects a refund. A refund cannot be issued until the return is filed, and that can also delay credits you are counting on.
If you live or do business in an area affected by a natural disaster or another qualifying event, you may have more time. The IRS periodically postpones deadlines for affected taxpayers, and on September 30 it announced relief for eligible taxpayers affected by ongoing events in Israel. The Journal of Accountancy also reported on October 11 that the AICPA is urging states to request federal disaster relief under a newer law, since a governor's declaration alone does not automatically trigger IRS postponements. Do not assume you qualify; check the IRS disaster relief page or ask us.
What happens if you miss it
The penalties are not small. As the Yahoo Finance report explains, the failure-to-file penalty is generally 5% of the unpaid tax for each month or part of a month a return is late, up to 25%. The failure-to-pay penalty is generally 0.5% per month, also capped at 25%, and interest is charged on both the unpaid tax and the penalties. In plain terms, the filing penalty is roughly ten times steeper than the payment penalty. That is why we almost always tell clients the same thing: file on time, even if you cannot pay the full balance yet.
Practical steps for the next few days
Here is a simple checklist to work through this week:
Gather what is still missing. Common holdouts are K-1s, 1099s, brokerage statements, mileage logs, and year-end bookkeeping adjustments.
Close out your 2025 books. If your profit-and-loss statement is not reconciled, that is usually the biggest bottleneck for a business owner.
File by Thursday, October 15, ideally electronically, so you get a confirmation that the IRS received it.
Pay what you can. Paying even part of the balance reduces penalties and interest. The IRS accepts payments through your IRS Online Account, Direct Pay, and the Electronic Federal Tax Payment System (EFTPS).
Ask about a payment plan if you cannot pay in full. The IRS offers installment options, and setting one up is usually much better than ignoring a balance.
Protect your information. October is Cybersecurity Awareness Month, and the IRS is reminding taxpayers to use strong, unique passwords, turn on multifactor authentication, and be wary of unexpected calls or messages asking for personal or financial details. The IRS generally contacts taxpayers first by mail.
Look ahead. Once this return is filed, it is a good time to review your 2026 estimated payments before the January installment.
We are here to help
Deadline weeks can feel stressful, especially when you are also running a business, but you do not have to sort it out alone. If you are still waiting on documents, are not sure whether disaster relief applies to you, or need help setting up a payment plan, contact Count The Cost Accounting today. We will help you get your return filed accurately and on time, and then help you plan so next year feels a lot calmer.
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